Here is the pattern: the mechanisms after impasse and how the different players acted to achieve their desired goal.

The part that should interest us that they were released to the cool down period despite the economic consequences of a possible strike, the establishment of a PEB by the president, the willingness of congressional republicans to impose the PEB recommendations, the democrats blocking it but ended up being used by the administration as the basis for the deal made at the table anyway.

Senator Sanders blocked the deal that the Biden administration essentially forced the union negotiators to take. Senate republicans proposed imposing the recommendation of president Biden’s PEB, which is largely what they eventually agreed to.

https://thehill.com/homenews/senate/...pt-labor-deal/

But not over yet as all the unions have to vote on this proposal. So we may yet see congress involved.